Saturday, October 15, 2016

As Oft' Happens -- A Smallish (Potential) Mission Glitch Emerges -- For NASA JPL's Juno Spacecraft...


Considering the harsh environment (crazy hot radiation @ 20 million RAD; a magnetic field 20,000 times stronger than Earth's -- and mostly minus 280 degrees Fahrenheit, hurtling 163,000 mph through space), at 520 million miles from an Earth repair (when it takes over 48 minutes one-way, for data traveling at the speed of light, to reach it) -- this is, I suppose, to be expected. [Earlier backgrounder here.]

Overnight, NASA and Cal Poly's JPL announced that the basketball-court sized Juno spacecraft will stay in its longer, more elliptical orbit (taking another 53 days to loop around the top of Jupiter) for one additional pass at least. Thus the tightening of its belt around Jupiter, to around 14 Earth-days per loop -- will have to wait a tic. Or a tock.

The craft will still collect all the expected data -- and is in a stable position to keep the mission rolling, but if the glitch is not solved, it may take several more months (at the longer 53 days per loop) to garner a statistically meaningful amount of data on what lies beneath those wildly boiling Jovian cloud-tops. [The spacecraft gets just completely hammered by massive doses of Jovian radiation, each time it dips in close -- to those tempestuous clouds. Perhaps the valve controller circuits (including backup controller circuits) have already been mostly fried.]

Here is the full release -- and a bit:

. . . .The decision was made in order to further study the performance of a set of valves that are part of the spacecraft’s fuel pressurization system. The period reduction maneuver was the final scheduled burn of Juno’s main engine.

"Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft’s main engine did not operate as expected during a command sequence that was initiated yesterday,” said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. “The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine.”

After consulting with Lockheed Martin Space Systems of Denver and NASA Headquarters, Washington, the project decided to delay the PRM maneuver at least one orbit. The most efficient time to perform such a burn is when the spacecraft is at the part of its orbit which is closest to the planet. The next opportunity for the burn would be during its close flyby of Jupiter on Dec. 11. . . .


[It has occurred to me (over my Saturday morning coffee and a banana) that I may still write on some ancillary matters related to pharma and life sciences -- and of course, my beloved space sciences -- mostly on weekends. So do look for more robust activity -- on weekends here, from time to time. We will keep a good thought for the solving of this glitch, if a glitch it be.]

Even so, she herself is sailing right along now, entirely care-free, with one other copper colored, twisting shepherd moon-lette I have long admired, mostly from afar. Smile. . . .

नमस्ते

2 comments:

Anonymous said...

Hello. I posted a comment on an earlier post that I thought was going to be anonymous, but I believe it may not have turned out that way. I would appreciate it if you could delete.

condor said...

It was in fact anonymous. I hope you're okay with me leaving it up. If not, just say -- and I'll pull it. It just went to the moderation queue, since that post entry/article was more than 36 hours old.

It's been my pleasure...

Namaste